Re: [PATCH v4] fs: forbid invalid project ID

[Wang Shilong <wangshilong1991@gmail.com>]

Anyone take this patch to the tree? maybe Al Viro?

On Sat, Jul 10, 2021 at 10:40 PM Wang Shilong <wangshilong1991@gmail.com> wrote:
>
> From: Wang Shilong <wshilong@ddn.com>
>
> fileattr_set_prepare() should check if project ID
> is valid, otherwise dqget() will return NULL for
> such project ID quota.
>
> Signed-off-by: Wang Shilong <wshilong@ddn.com>
> ---
> v3->v3:
> only check project Id if caller is allowed
> to change and being changed.
>
> v2->v3: move check before @fsx_projid is accessed
> and use make_kprojid() helper.
>
> v1->v2: try to fix in the VFS
>  fs/ioctl.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index 1e2204fa9963..d4fabb5421cd 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -817,6 +817,14 @@ static int fileattr_set_prepare(struct inode *inode,
>                 if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
>                                 FS_XFLAG_PROJINHERIT)
>                         return -EINVAL;
> +       } else {
> +               /*
> +                * Caller is allowed to change the project ID. If it is being
> +                * changed, make sure that the new value is valid.
> +                */
> +               if (old_ma->fsx_projid != fa->fsx_projid &&
> +                   !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
> +                       return -EINVAL;
>         }
>
>         /* Check extent size hints. */
> --
> 2.27.0
>